Gunmen killed five Egyptian soldiers near the Suez Canal city of Ismailia on Monday, security sources said, in a series of attacks that highlight growing insecurity since the army ousted Islamist President Mohamed Mursi.

In an interview published on Monday, Egypt's army chief said he had told Mursi as long ago as February that the president had failed, about five months before the military removed him.

General Abdel Fattah Al-Sisi made the remarks before dozens died on Sunday in clashes involving security forces, supporters of Mursi's Muslim Brotherhood and their opponents.

The security sources said the gunmen opened fire on the soldiers while they were sitting in a car at a checkpoint near Ismailia on the Canal, a vital global trade route.

In a separate incident, an explosion near a state security building in South Sinai killed two people and injured 48, medical sources said. A witness said the explosion was caused by a car bomb.

In the most brazen attack of the day, assailants fired a rocket-propelled grenade at a state-owned satellite station in the Maadi suburb of Cairo on Monday, wounding two people, security officials said.

Attacks by Sinai-based militants have risen sharply since the army toppled Mursi and promised a roadmap that would lead Egypt to free and fair elections.

Almost daily attacks by Al Qaeda-inspired militants in the Sinai have killed more than 100 members of the security forces since early July, the army spokesman said on September 15.

Militant violence elsewhere in Egypt has raised fears that an Islamist insurgency, like one eventually crushed in the 1990s by then president Hosni Mubarak, could take hold beyond Sinai.

The militant attacks, including a failed assassination attempt on the interior minister in Cairo in September, are deepening insecurity in Egypt along with the power struggle between the Brotherhood and the army-backed government.

The death toll from clashes in Egypt rose to 53 on Monday, state media said, as calm returned to the streets after one of the bloodiest days since the military deposed Mursi.

SECURITY FORCES TAKE CONTROL

Traffic flowed normally in central Cairo where thousands of Mursi supporters had battled security forces and army supporters on Sunday on the anniversary of the 1973 war with Israel.

State radio said security forces had regained full control of Egypt, which signed a peace treaty with Israel in 1979. In addition to the dead, state media said 271 people had been wounded in the clashes. Most of the casualties were Mursi supporters, security sources said.

Further confrontations may shake Egypt this week. An alliance that includes the Muslim Brotherhood has urged Egyptians to stage more protests against the army takeover from Tuesday and gather on Cairo's Tahrir Square on Friday.

Political turmoil since the army unseated Mursi on July 3 has unnerved foreign investors and hammered tourism, a pillar of the economy, but there is no sign of reconciliation between the Brotherhood and the army-backed government.

Security forces smashed pro-Mursi protest camps in Cairo on August 14, killing hundreds of people. In an ensuing crackdown, many Muslim Brotherhood leaders were arrested in an attempt to decapitate Egypt's oldest Islamist movement.

Authorities had warned that anyone protesting against the army during Sunday's 1973 war anniversary would be regarded as an agent of foreign powers, not an activist - a hardening of language that suggests authorities may crack down harder.

The Brotherhood remains defiant, organising demonstrations, even if they are much smaller than ones staged weeks ago.

Army chief Sisi, in an interview published in a privately owned newspaper, Al-Masry Al-Youm, said Egypt's national interests differed from those of the Brotherhood as an organisation.

In the interview conducted before Sunday's violence, Sisi also spoke about his previous meetings with Mursi, whose time in office he said had driven Egypt in the direction of civil war.

"I told Mursi in February you failed and your project is finished," Al-Masry Al-Youm quoted Sisi as saying.

Sisi denied Brotherhood allegations that the army had intended to remove Mursi through a coup, saying it had only responded to the will of the people.

Before Mursi's overthrow, Egyptians disillusioned with his year-long rule had held huge rallies demanding that he quit.

Last month, a court banned the Brotherhood and froze its assets, pushing the group, which had dominated elections held in Egypt after Mubarak's fall in 2011, further into the cold. - Reuters